1. Field of the Invention
The present invention relates to a method of determining a drive lane, and more particularly, to a method of accurately determining the drive lane of a road using a precise digital map capable of differentiating the lanes of the road and carrier-based differential GPS having a high accuracy capable of differentiating the lanes of the road as well as a steering wheel model of a vehicle.
2. Description of Related Art
Generally, a navigation device which is widely used in a vehicle in order to assist a driver is to provide route information to the driver's destination. A driver can see a map displayed on a terminal of a navigation system or listen to voice message while driving a car.
The navigation device functions to combine location information obtained from GNSS (global navigation satellite system) and geographic data of a digital map and then to display a vehicle position on a road displayed on the map.
However, a conventional navigation device can just indicate rough road information, but cannot indicate precise information about a drive lane occupied by a vehicle. In other words, the conventional navigation device can guide only route and direction information to a destination, but cannot guide the route on the basis of the drive lane of the road on which a vehicle is running. For example, in case that the vehicle which intends to turn left runs on other lanes except the first lane, the conventional navigation device could not inform of lane change.
Therefore, there is a problem in that, since a driver has to recognize and determine the conditions around the vehicle and the actual drive lane occupied by the vehicle and then to change the lane, it is limited to provide practical information to the driver.
In order to solve the problem, the inventors have proposed a method of determining the drive lane using precise GPS information capable of differentiating each road lane and a precise digital map capable of displaying the lane information, which has been filed and issued as a patent (Korean Patent No. 10-1010678 entitled “a navigation device and a drive lane determining method thereof”).
In the drive lane determination method, a vehicle position is estimated on the basis of satellite signals received from a carrier-based navigation satellite system and compensation information received from a station, and an extent of lane differentiation is halved by determining a drive direction of the vehicle using vehicle location information and road lane information stored in a digital map, and a distance between a center line of each lane and a vehicle location is calculated by using the vehicle location information and the road lane information, and the road lane having a minimum value among the calculated distances is determined as a drive lane. In this method, however, the drive lane of a running vehicle is differentiated only using the satellite signals and the road lane information. Therefore, even when an error is occurred in the lane differentiation, it is impossible to correct the error, and thus reliability in the lane differentiation is deteriorated.